init = function() {
  if (document.all && document.getElementById) {
    mainMenu = document.getElementById("main-menu");
    for (i = 0; i < mainMenu.childNodes.length; i++) {
      menuNode = mainMenu.childNodes[i];
      if (menuNode.nodeName == "LI") {
        menuNode.onmouseover = function() { this.className += " mouseover"; }
        menuNode.onmouseout  = function() { this.className = this.className.replace(" mouseover", ""); }
      }
    }
  }
}
window.onload = init;